The subject matter disclosed herein relates to a power converter with a modular, compact architecture with a reduced component count. More specifically, the power converter includes parallel power conversion sections and utilizes one or more mutual coupling input inductors with multiple windings connected in pairs in a differential mode between a power source and the parallel power conversion sections resulting in current balancing and sharing between each branch of the parallel configuration.
As is known to those skilled in the art power converters allow for a controlled output voltage and/or current to be supplied from an input power source. The input power source may be an Alternating Current (AC) or a Direct Current (DC) voltage having a first amplitude and frequency. The output of the power converter may be either an AC or a DC voltage having a second amplitude and frequency, where the second amplitude and/or frequency is different than the first amplitude and/or frequency. The output of the power converter may be either fixed or variable according to the configuration of the power converter. Numerous configurations of one or more active or passive switching devices along with inductive or capacitive devices are arranged to provide the controlled output voltage.
In order to convert the voltage from the first amplitude and frequency at the input to the second amplitude and frequency at the output, the power converter utilizes one or more power switching devices, such as thyristors, silicon controlled rectifiers (SCRs), diodes, metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor (IGBTs), other power transistors, and the like. The power switching devices may be active or passive and a controller may generate switching signals to control operation of the active devices. The switching devices turn on and off at frequencies ranging from hundreds of hertz to hundreds of kilohertz in order to synthesize the desired output voltage from the input voltage.
Switching the devices on and off, however, creates an electrically noisy environment with undesirable conducted and/or radiated emissions. The undesirable conducted emissions include transient voltages and/or currents at the input and output of the power converter. In order to limit the undesirable conducted emissions, filtering devices may be connected at the input or output. As the power rating of a power converter increases, the switching devices as well as the filtering devices must be sized accordingly. Increasing the power rating of the switching devices and/or the filtering devices typically results in an increase in cost, due for example to more expensive materials; an increase in size to handle the increased current capacity-, or a combination thereof.
At high power levels, the devices can either no longer be rated to handle the desired power or the cost of devices that can be rated to handle the desired power is too great. Historically, these drawbacks have been overcome by providing multiple power conversion sections operating in parallel. Each power conversion section handles a portion of the power for the system and, therefore, the components for each section need only be rated to handle the corresponding portion of the power.
However, such systems are not without drawbacks. Each power conversion section requires its own filters and switching devices. As a result, the physical size of the system increases.
It is a first feature of the invention to provide a paralleled power converter system with a reduced size.
It is another feature of the invention to provide a paralleled power converter system with a reduced component count, which, in turn, reduces cost and further reduces size.
It has also been known to provide separate controllers to control each power conversion section. The controllers of each power conversion section must be synchronized to operate together and to produce the desired output voltage. Synchronization requires communication between the controllers. As previously indicated, the rapid switching of the switching devices creates an electrically noisy environment. The electrical noise may cause errors in the communication between controllers or require additional shielding to prevent the errors from occurring.
It is still another feature of the invention to provide a paralleled power converter system which does not require communications between power conversion sections.